Description: These isopods are narrow
and elongate. They reach about 42 mm in length and have a telson
with right lateral angles and an acute median spine. Colors of these
isopods may vary and this may be due to the habitat in which they choose
to live. The maxiilliped
consists of 4 articles and the pleon
consists of 2 free pleonites
plus the pleotelson,
which has a pair of lateral incisions indicating the posterior limits of
another partly free pleonite.

How to Distinguish from Similar Species: They
have a telson similar to Idotea stenops and the Idotea schmitti.
However, I. fewkesi are far more narrow and elongated.

Geographical Range: Alaska to central
California

Depth Range: Commonly found in the
subtidal zone (8-12 meters) although a few may be found in the intertidal
zone.

Habitat: Live on algae on exposed
rocky coasts or subtidally.

Biology/Natural History: Females appear
to be ovigerous
in July and October. Not much can be said about these subtidal isopods.
Their pigmentation may be affected by the substrate on which they live.